A curtain wall is a non-structural exterior wall system used in modern buildings to protect the interior from weather while allowing natural light and creating a clean architectural appearance. Unlike load-bearing walls, a curtain wall does not carry the weight of the building itself. Instead, it hangs from the building’s structural frame, transferring its own weight and the environmental forces it receives, such as wind pressure, rain, and temperature changes, back to the main structure. This separation of structural and enclosure functions makes curtain walls a key feature in contemporary high-rise, commercial, and institutional architecture.Curtain walls are commonly made from lightweight materials such as aluminum, glass, steel, and composite panels. Among these, aluminum framing and glass infill are the most widely used because they offer strength, corrosion resistance, and an elegant appearance. The system is designed to be thin and visually lightweight, which helps create large transparent surfaces and a sense of openness. This makes it especially popular in office towers, shopping centers, hotels, airports, and cultural buildings where daylight, views, and modern aesthetics are highly valued.A curtain wall system typically includes vertical mullions, horizontal transoms, glass or panel infill, seals, gaskets, anchors, and drainage components. These parts work together to resist air and water infiltration, accommodate building movement, and maintain thermal performance. Because buildings expand, contract, and shift slightly over time, the curtain wall must be flexible enough to absorb these movements without cracking or leaking. Proper engineering and installation are therefore essential to ensure long-term durability and performance.There are several types of curtain wall systems, including stick systems, unitized systems, and structural glazing systems. Stick systems are assembled piece by piece on site, offering flexibility for smaller or more complex projects. Unitized systems are prefabricated in factory conditions and installed as large panels, which can improve quality control and speed of construction. Structural glazing systems minimize visible framing and produce a smooth, seamless facade appearance. Each type has its own advantages depending on project scale, budget, schedule, and design goals.Curtain walls also contribute significantly to energy efficiency when properly designed. Modern systems often incorporate insulated glass, low-emissivity coatings, thermal breaks, and shading devices to reduce heat gain and heat loss. This helps improve indoor comfort and lower energy consumption. In addition, curtain walls can support sustainable design strategies by maximizing daylight and reducing the need for artificial lighting during daytime hours.Maintenance is another important aspect of curtain wall performance. Regular inspection of seals, joints, and drainage paths helps prevent air leaks, water intrusion, and material deterioration. Cleaning glass surfaces and checking for damaged components also preserves appearance and functionality. With careful design, installation, and upkeep, a curtain wall can provide both aesthetic value and reliable protection for many years, making it one of the most important elements in modern building envelope design.